Teacher assistants work under a licensed teacher's supervision to give students of all ages additional attention and instruction, either one-on-one or in small groups. Teacher assistants also called teacher aides and paraprofessionals monitor students' progress, and help them to learn the material that teachers present. Assistants may grade tests and check homework, or for young children at childcare centers, they may supervise playtime, and help with feeding and basic care. Some teacher assistants work only with special education students. Assistants may adapt material to the student's learning style and help with understanding, while for students with more severe disabilities, teacher assistants help with basic needs, such as eating and personal hygiene. With young adult students who have disabilities, assistants may teach skills necessary for finding a job or living independently after graduation. Some teacher assistants supervise students in a specific location, such as computer labs, recess, or in the lunchroom. Part-time schedules are common for teacher assistants, sometimes including riding the bus with students before and after school. Many work the nine-month school year, though some also work summers. Teacher assistants have a high rate of illnesses and injuries. Teacher assistants typically need to have completed at least two years of college coursework, or an associate's degree.